Transfers from one ship to another are an important part of the shipping business. The idea of ship-to-ship transfers originated in an era when large ships were too big to reach all ports. As a result, they were anchored at sea. Smaller ships were then used to load and unload the cargo from the larger ships.
Today, this practice has developed into a complex process. It requires careful planning and execution. You will learn everything you need to know about ship-to-ship transfers in this guide. Including their importance, how they work, and tips for a smooth transfer.
What Is Ship-to-Ship Transfer?
Ship-to-ship transfer (STS) is the transfer of goods from one ship to another while at sea or at the outer harbor limits. This process is important for many reasons, such as transporting crude oil, bulk goods, or other petroleum products. In most cases, STS operations are used to increase the efficiency of port calls and avoid port congestion and its associated costs. It can also be used to transfer goods that are difficult to handle during a normal port call.
When is Ship-to-Ship Cargo Transfer Required?
There are several situations in which cargo may need to be transferred from one ship to another. In most cases, the following situations occur:
Transporting Personnel or Equipment Between Two Ships
Sometimes an STS operation is required to transfer personnel or equipment from one ship to another. This may be necessary for maintenance or emergency repairs. This keeps the ship running smoothly without having to return to port.
Cargo Transfer From Offshore Supply Vessels
Supply vessels are often used to transport vital supplies to larger vessels operating offshore, especially in oil field operations. This transfer from one vessel to another is important to keep offshore platforms running and to ensure that the mother ship gets the supplies it needs.
Crew Changes
STS operations also make crew changes easier. This is very useful when the ship is on a long journey or in a remote location. This method of operation saves time and money. Because the new team can take over without the ship having to dock.
Certain Types of Cargo
At sea, certain types of cargo are often transferred from one ship to another. These include oil, liquefied natural gas (LNG), and other large goods. Special tools and methods are required to ensure that the transfer is completed safely and quickly.
How is an STS Transfer Carried Out?
To carry out an STS transfer smoothly, you need to plan properly. There are several things to consider during the planning stage to ensure a safe and smooth process. Some of these are:
Vessel Dimensions and Their Impact
It is important to consider the dimensions of the vessels involved in the transfer. This is because interactions can affect the stability and maneuverability of the vessels. Understanding these effects is important for planning the method of operation and securing the vessels safely.
Number of Mooring Supervisors
It is important to know in advance how many mooring supervisors are required for the task. These supervisors help to ensure that the vessels are safely moored and the transfer goes smoothly.
Prepare Communication Tools
Good communication is essential for STS operations. Before the operation begins, everyone should agree on the communication methods and ensure that they are effective. Everyone should use the same language. In addition, there should be a backup communication method in case the main method fails.
Course and Speed
It is important to clarify which ship maintains course and speed (the constant ship) and which ship moves during the operation. This way, both ships can plan the operation safely and successfully.
Daylight Hours
Some operations, especially those involving very large crude carriers (VLCCs), may need to take place during daylight hours. This affects the timing of the operation to ensure it is carried out in the safest and most visible way.
Wind Speed and Direction
Wind speed has a significant impact on the way STS operations are carried out. There are clear thresholds for wind speed, which is normally limited to 30 knots. However, for larger vessels, the wind speed limit is even lower. Wind direction is also important, as it affects steering, especially in the case of adverse currents.
Wave Limits
In most cases, the height of the waves is limited to around 3 meters. For VLCC transshipments, the wave limit is 1.5 meters. These limits ensure that the ship remains stable during the STS operation.
Weather Planning
In order to plan an STS operation, an accurate weather forecast is essential. The forecast must be kept within a reasonable range. In addition, extra time should be allowed in case of unplanned delays.
Sea Floor Clearance
Safe operations require an unobstructed and clear sea with a certain distance (e.g. 10 nautical miles). This allows the ship to work without incident and with sufficient space.
Approach Speed
To dock safely, it is also important to control the approach speed, which is usually between 5 and 6 knots. The speed may be affected by the load limit of the anti-collision device. In addition, the moving ship should not point in the wrong direction. The most common approach is from the quarter of the mooring side.
These are some of the preparations that need to be made for a smooth STS operation. However, the specific situation may require different factors to be considered. It is important to work with all relevant personnel and carry out a thorough risk assessment before starting any STS operation.
Requirements for STS Transfer Operations
In addition to preparing for an STS operation, there are things that need to be done to ensure a smooth and safe transfer process. These include the following areas
Adequate training of tanker crew
The crew on the tanker needs to be properly trained, which is important for an STS transfer operation. The crew must be aware of the procedures and safety rules for an STS transfer operation.
Correct STS Equipment
Both ships that need to be transferred must be equipped with the correct STS equipment in good condition. This includes air cushions, hoses, and any other equipment needed for the move.
Clear Lines of Communication
For an STS transfer operation, it is important that the two vessels can communicate clearly with each other. This helps the operation to run smoothly and any problems that may arise to be dealt with.
Thorough Planning
Before an STS transfer operation, the actions need to be carefully planned in advance. This includes informing the relevant people about how much cargo will be transported and what type of cargo it is. During the transfer, it is important to pay close attention to the changes in the freeboard and inclination of each vessel.
Obtain Approval From the Port Authorities
One of the most important steps in the preparation process is to obtain the correct approval from the port authorities. This ensures that the process is legal and complies with local regulations.
Understand the Nature of the Goods
Another important part of the process is to understand the nature of the goods being transported. This means, for example, having the Material Safety Data Sheets (MSDS) and UN numbers to hand in case of an emergency.
Comprehensive Safety Briefing
The entire team involved in the transport should receive a comprehensive safety briefing. This should include a discussion of the risks posed by the cargo. Examples include volatile organic compound (VOC) emissions and chemical reactions.
Firefighting and Oil Spill Equipment
Every ship must be equipped with firefighting and oil spill equipment to reduce risks. Examples include fire extinguishers, hoses, and control arms. In an emergency, the crew should know how to use this equipment correctly.
Comply with the Rules
You must comply with all the rules listed in MEPC 59, MARPOL Annex 1 Chapter 8, SOPEP, SMPEP, Ship Transfer Guidelines, and the operational plan. This ensures that international rules are followed and safe STS operations are carried out.
Conduct a Risk Assessment
A thorough risk assessment should be carried out to identify any potential hazards and take steps to reduce the risks. This includes checking the temperature, sea conditions, and other environmental factors.
Prepare an Emergency Response Plan
It is important to prepare a response plan for emergencies. This should include procedures for dealing with leaks, fires, and other eventualities that may arise during transport.
If you follow these rules, you can significantly reduce the risk of collisions and damage to the environment. Good STS transfer operations depend on thorough preparation and following the rules.
Compliance with Regulations
As we have already said, compliance with regulations remains very important in STS operations. This ensures everyone’s safety, just as it does during normal port calls. It is therefore important to be aware of the latest rules, both foreign and local.
The International Maritime Organization (IMO) has strict rules for STS operations. A new chapter 8 has been added to MARPOL Annex I, which describes how to prevent pollution during STS missions. This is an important update. In addition, this chapter only applies to tankers over 150 gross tons and does not apply to refueling or platform operations.
Important rules and regulations include:
- STS Operation Plan: The STS operation plan needs to be approved by the authorities and should be available in the main languages on board.
- Record Keeping: You must keep a complete record of STS operations in the Oil Record Book for three years.
- Notification: The coastal authorities need to be informed of operations 48 hours in advance.
If the ship’s agent understands and complies with these rules, then they can carry out safe, legal, and environmentally friendly STS transfer operations.
STS Transfer Safety
In addition to having a contingency plan in place, a number of safety measures should be taken during an STS movement. These include
Notifying the Relevant Authorities
STS transfer operations need to be reported to the relevant authorities. This includes the coastguard, port authority, and any other necessary bodies. Failure to notify these authorities correctly could result in fines or penalties. This also includes obtaining the correct permits and complying with the rules in your area.
Person in Charge
STS operations require a person in charge. This person is responsible for ensuring that all steps are carried out correctly and for planning what the crew should do. In an emergency, they are also responsible for supervising the transfer process and making any choices that need to be made.
Choosing the Right Transfer Area
To ensure that everything goes smoothly and safely, the transfer location must be chosen carefully. You should consider factors such as the weather, traffic, and how close it is to the coast. In addition, you should choose a location that is sheltered from strong winds and currents and away from busy trade routes. You should also consider how deep the water is, as STS operations need to take place in water that is deep enough.
Risk of Liability
Understanding and reducing risk is another important part of the business. As part of this, they must ensure that they have adequate insurance and meet all legal requirements. It is also important to have clear rules and guidelines for communication for everyone involved in STS operations.
Use the Right Tools
As we said earlier, using the right equipment and keeping it in good condition is important for smooth STS operations. Different types of STS operations will have different requirements. But there are some things that should always be taken into account. Some of these are having good pipes and couplings, the right fender systems, and the right mooring arrangements.
Have a Contingency Plan
It is important to follow the rules and use an STS operation plan. However, it is also a good idea to have a contingency plan just in case. This plan should include measures to be taken in the event of an emergency, such as damage to the equipment or bad weather. There should also be a way to communicate with the relevant people to keep them informed.
The contingency plan should be drawn up for each STS operation, taking into account factors such as the location and type of vessel. The contingency plan should also be reviewed and revised regularly. This ensures that it remains up to date and complies with any new regulations.
Summary
Ship-to-ship transfer is an important part of maritime activities. It avoids overcrowding in ports by transferring cargo between ships. Ship agents must be fully aware of the standards, safety measures, and preparatory steps. To manage risks and ensure smooth transfers, advance planning, clear communication and strict adherence to safety rules are essential.
